A new study that looks at the impact of peer-to-peer (P2P) traffic on service provider networks shows that file swapping forges on unabated.

CacheLogic, a Cambridge monitoring firm, says the practice shows no sign of slowing down, despite court rulings that have shut down some popular sites, such as Suprnova, a BitTorrent tracking service that offered links to pilfered television and movie content.

CacheLogic's global monitoring network shows that 60 per cent of all internet traffic is the result of P2P file-sharing platforms, with eDonkey taking over the top spot from BitTorrent.

"The Whack-A-Mole game continues," says Andrew Parker, CacheLogic's CTO. "The authorities go after one [P2P] system and another one pops up."

At the end of 2004, BitTorrent accounted for 30 per cent of internet traffic. But after the Motion Picture Association of America's moves to shut down BitTorrent tracking sites - centralised servers for locating distributed content - swappers began moving to other less-publicised services.

Today, eDonkey, a system that uses no centralised servers or tracking sites, consumes the most bandwidth of any application on the internet, according to Parker. And in the US, Gnutella has seen resurgence in popularity among swappers.

Of the files being swapped on the four major file-sharing systems (eDonkey, BitTorrent, FastTrack and Gnutella), 62 per cent are video and 11 per cent are audio, with the rest made up of miscellaneous file types, according to the study.

The problem for ISPs is that the traffic is symmetric, meaning the same amount of traffic going downstream (where the pipe is bigger) is coming back up, choking the smaller upstream broadband pipes. And traffic is constant, unlike email and web surfing, which tails off during the night.

In addition to releasing internet traffic details, CacheLogic has announcing that it is looking to expand its monitoring network by offering free equipment to selected service providers. CacheLogic and the ISP would share the traffic analysis data.

P2P filesharing does have some legitimate uses, as it pushes the distribution load away from a central origin server and out to the very edge: each individual user/viewer.

The BBC has launched iMP, a download service that relies on P2P technology to deliver television programming to subscribers. Each program could be multi-gigabyte; this would be nearly impossible to serve to all BBC subscribers from a central location, Parker says.

For more information on network monitoring, our sister site Techworld has a comprehensive network monitoring resource page.